1. Field of the Invention
The present invention relates generally to high-precision modular measuring instruments, and more particularly to a modular pressure sensor drive connectable to a computer.
2. Description of the Related Art
Many measuring instruments are commercially available to monitor a variety of conditions such as pressure conditions. An example of a high precision absolute pressure sensor is the model 6000 digital pressure standard manufactured by Labersav, Inc. of Houston, Tex. Absolute pressure sensors measure pressure in absolute terms, i.e., as a pressure difference with respect to a vacuum. Relative pressure sensors measure pressure in the form of a pressure difference with respect to a reference pressure. The reference pressure can be an ambient pressure, which may be the atmospheric pressure at the location of use. Other types of measuring instruments may include current and voltage sensors, smoke sensors and temperature sensors.
Measuring instruments are generally comprised of sensing elements combined with support equipment, for example, electronics, processing components, display components and user controls. During the design phase of a measuring instrument, a great deal of time and resources are expended to select, design, configure and integrate hardware and software to ensure that the resulting measuring instrument functions properly. Often, the design process is specific to the measuring instrument being designed, resulting in hardware and software that is not readily reusable. Consequently, updating the measuring instrument to a new design generally requires a complete redesign. Therefore, the conventional approach is neither efficient nor cost effective.
In addition, when measuring accuracy is paramount, the measuring instruments require periodic calibration. The calibration process generally requires the removal of the measuring instrument from duty, thus resulting in an interruption in service. It is therefore advantageous, both for the user on site and for the manufacturer of the measuring instruments, for reasons of calibration, maintenance and portability, to design measuring instruments as a modular assembly. Modular interchangeability of measuring components reduces the manpower associated with removing instruments from service, reduces shipping costs if measuring instruments must be shipped offsite for calibration, and minimizes down time by allowing field-swapping of calibrated sensing elements. Thus, it should be appreciated that there is a need for a modular measuring instrument that overcomes the drawbacks of conventional measuring instruments. The present invention fulfills this need as well as others.